Multiply your projector image with a prism & mirrors
I am experimenting with the idea of having several "cloned screens" out of one projector. The principle of light being split by a prism may yield very good results if colors are correctly displayed when using the prism with two mirrors to split the light in two directions. I will try this with an overhead projector first but if anybody has any suggestions please feel free to comment.
Having the same image duplicated has a lot of advantages for projected movies in the park and businesses. Superbolw! Hockey! times two!